To provide a speaker components of the magnetic circuit of which are easily sorted and disposed of, and to provide a method for manufacturing the speaker and a method for dismantling the speaker.

This speaker is provided with a magnetic circuit, a frame, a diaphragm, and a voice coil, and the magnetic, pole piece, and plate of the magnetic circuit are fastened by a fastening member made of shape memory alloy. The magnetic circuit of the speaker is heated at a magnetic circuit destruction temperature(that is, a temperature which is not less than a shape restoration temperature and an irreversible demagnetization generation temperature) or more so that the fastening of the magnetic circuit can be released, and that the magnet can be demagnetized. Then, the speaker can be dismantled into the components of the magnetic circuit.